Firefox comes in two or more folders on all computers. They are; Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And one folder in the profile of each user on the computer. If each user has their own user ID, there should be no problem.

I do not currently use Mac s. I do use Linux & sometimes Windows, they all allow user accounts to be setup with or without passwords. When Firefox is installed it is usually installed globally and available to all users, without any need to use a password to specifically access Firefox. Each user account will use a separate Firefox profile. Your Firefox info: passwords, bookmarks, browsing history etc. is in the profile * [[Profiles - Where Firefox stores your bookmarks, passwords and other user data]] It is good general practice to have separate user accounts for separate people (or groups of people) and even for separate purposes. For instance you may let children all use the same account but have a separate account for your spouse, and separate accounts for your day to day use and computer Admin tasks. Also you may if you wish set up additional Firefox Profiles. This is slightly complicated. So if you set up an OS account Kids, it could then have profiles child1, child2 with their own shortcuts and profiles. * [[Use the Profile Manager to create and remove Firefox profiles]] * https://developer.mozilla.org/Firefox/Multiple_profiles '''You may find this article of interest''' * ''Creating New User Accounts on Your Mac Learn About the Various Types of User Accounts'' http://macs.about.com/od/switchersnewusers/tp/accounthub.htm